A WATER expert from the US has questioned the £4.1billion super sewer, saying there are cheaper, greener and less disruptive alternatives to keeping filth out of the River Thames.
Utility giant Thames Water has caused consternation in Fulham with its plans to build part of the 20-mile-long sewage pipe at Carnwath Road, which would mean up to seven years of disruption to hundreds of residents.
Politicians have questioned the cost of the project, and further fuel has been added to the fire by the man who is helping solve sewage problems in Philadelphia with a ‘green’ solution.
Dr Mark Maimone, vice-president of CDM Smith, is overseeing a transformation of the city’s waste disposal systems, with permeable pavements, green roofs and infiltration trenches to stop fresh rain water flooding into sewers.
He believes London should follow this example and consign the idea of a tunnel-based solution to the scrapheap.
Speaking last week, he said: “There is more space here than there is in the denser areas of Philadelphia where we are doing it right now and Philadelphia has to handle twice the number of combined sewer overflows than London does.”
Speaking to the House of Lords, Dr Maimone warned Thames Water not to follow the example of Portland, America, where a tunnel failed to stop sewage flowing into their river.
The city then embarked on a green infrastructure programme, resulting in it paying twice for one drainage solution.
He also addressed residents in St Mary’s Church, Putney Bridge, including Fulham activist Ann Rosenberg.
She said: “The Thames Tunnel would deal with the symptom and not the problem. Over time, the climate is becoming more unreliable and the tunnel is a very inflexible solution. It may be overused during times of drought and unable to cope during excessive rainfall."
Hammersmith and Fulham Council leader Nick Botterill said: “The evidence is clear – green infrastructure that prevents fresh water from overloading the sewer network is the best way to stop sewage from flowing into the Thames.
“The main reason Thames Water fails to listen to what the experts have to say is because it stands to make huge profits from the scheme.”
Thames Water insists the tunnel is the best way to stop 39 tonnes of sewage entering the river every year.